1. Technical Field
The present invention relates to an inkjet recording machine configured to eject drops of ink in an ink chamber from a nozzle.
2. Related Art
In an inkjet recording machine, ink in an ink chamber provided at an inkjet head is ejected as a drop from a nozzle. The ink drop ejected from the nozzle flies with a tail, and there are a time lag and a speed difference between a head portion and a tail portion of this drop in flight. Thus, accompanying a preceding main drop, unnecessary minute drops (satellite drops) might be produced. The satellite drops (also called mist) degrade the printing quality by attaching onto a recording medium, and contaminate the device by attaching to the inside of the device.
Such satellite drops are produced in the same way in both a serial-type recording machine and a line-type recording machine. In the serial-type recording machine, an inkjet head on a carriage reciprocates in a main scanning direction which is orthogonal to a conveyance direction of the recording medium. In the line-type recording machine, a line head extending over the entire length in the main scanning direction is formed by arranging multiple head blocks each provided with multiple nozzles.
For example, Japanese Patent Application Publication No. 2007-136847 proposes a technique of forcibly sucking the satellite drops to prevent the satellite drops from flying to, for example, portions other than proper landing positions on a recording medium or to portions of the device around the recording medium.
The satellite drops described above are produced more as the speed of ink ejected from the nozzles is increased in order to maintain the amount of ink ejected under a low temperature which increases the viscosity of the ink. To address this, Japanese Patent Application Publication No. 2010-105208 proposes the following technique for an inkjet recording machine configured to suck a recording medium to a belt platen by use of a negative pressure generated by a suction fan. Specifically, the technique prevents satellite drops from widely diffusing along with the air flow for sucking the recording medium, by reducing the amount of negative pressure generated by the suction fan when the temperature of the ink is low.